26 USB
248
EPSON
S1C38000 TECHNICAL MANUAL
bits 7–0
Endpoint 4 Max Packet Size Bits [7:0]
This register specifies the maximum packet size for endpoint 4 in units of 8 bytes
(default = 64 bytes). It can be read by the host through the endpoint 4 descriptor.
bits 7–0
Chip Revision Bits [7:0]
This register returns current silicon revision number of the USB client.
bit 7
Suspend Control
If set, this bit indicates that there is a pending suspend request from the USB host.
Writing a 1 clears this bit and causes the S1C38000 USB device to enter suspended
mode.
bit 6
USB Endpoint 4 STALL
The last USB IN token could not be serviced because the endpoint was stalled
(USB[00h] bit 4 set), and was acknowledged with a STALL. Writing a 1 clears this bit.
bit 5
USB Endpoint 4 NAK
The last USB packet transmitted (IN packet) encountered a FIFO underrun condition,
and was acknowledged with a NAK. Writing a 1 clears this bit.
bit 4
USB Endpoint 4 ACK
The last USB packet transmitted (IN packet) was successfully acknowledged with an
ACK from the USB host. Writing a 1 clears this bit.
bit 3
USB Endpoint 3 STALL
The last USB packet received (OUT packet) could not be accepted because the endpoint
was stalled (USB[00h] bit 3 set), and was acknowledged with a STALL. Writing a 1
clears this bit.
bit 2
USB Endpoint 3 NAK
The last USB packet received (OUT packet) could not be accepted, and was
acknowledged with a NAK. Writing a 1 clears this bit.
bit 1
USB Endpoint 3 ACK
The last USB packet received (OUT packet) was successfully acknowledged with an
ACK. Writing a 1 clears this bit.
bit 0
USB Endpoint 2 Valid
When this bit is set, the 8-byte endpoint 2 mailbox registers have been written by the
local CPU, but not yet read by the USB host. The S1C38000 should not write into these
registers while this bit is set.
Endpoint 4 Maximum Packet Size Register
USB[5Ch]
Default = 0000 0008h
Read/Write
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
n/a
Endpoint 4 Max Packet Size
15
14
13
12
11
10
98
76543210
Revision Register
USB[60h]
Default = 0000 0001h
Read Only
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
n/a
Chip Revision
15
14
13
12
11
10
98
76543210
USB Status Register
USB[64h]
Default = 0000 0000h
Read/Write
n/a
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
n/a
Suspend
Control
USB
Endpoint
4 STALL
USB
Endpoint
4 NAK
USB
Endpoint
4 ACK
USB
Endpoint
3 STALL
USB
Endpoint
3 NAK
USB
Endpoint
3 ACK
USB
Endpoint
2 Valid
15
14
13
12
11
10
98
76543210